A dispute over the ownership of a cross-border waterway has triggered the rapid spread of unauthorised oyster farms, MPs have heard.

Sharon McMahon of the Loughs Agency told the Northern Ireland Affairs Committee that Lough Foyle oysters could be worth £20m.

The industry in Lough Foyle is unregulated due to the political dispute over who owns the waterway, which straddles the Irish border. The authorities currently have no power to regulate or control the spread of the oyster farms, which have increased dramatically in recent years.

Ms McMahon said on the Northern Ireland side, the Department of Agriculture issued notices, but she said there are more oyster tables on the Inishowen side in the Republic. She described the situation as "quite urgent" and said it "should be a priority".

The public evidence session was held in Newtownards, Co Down yesterday as part of the committee's investigation into the fishing industry and potential impact on it from Brexit.